

🔋 Power your passion with precision and protection!
The HXJNLDC 503040 is a rechargeable 3.7V, 620mAh lithium polymer battery designed for smart devices like Cozmo and Vector robots, SkyBell HD doorbells, and FPV watches. It features advanced Japanese Seiko IC protection against overcharge, overcurrent, and short circuits, ensuring safe and reliable performance. Compact and lightweight, it supports easy DIY installation with included connectors and insulating sleeves, making it the go-to power upgrade for millennial tech enthusiasts seeking longevity and peace of mind.







| ASIN | B08PKV564B |
| Amperage | 0.6 Amps |
| Antenna Location | GPS, Radio, Watch |
| Battery Capacity | 620 Milliamp Hours |
| Battery Cell Composition | Lithium Polymer |
| Battery Cell Type | Lithium Polymer |
| Battery Weight | 13 Grams |
| Brand | HXJNLDC |
| Built-In Media | 620mAh battry x 1 pack, heat shrinkable insulating sleeve x 1 |
| Customer Reviews | 4.4 out of 5 stars 977 Reviews |
| Item Dimensions | 1.61 x 1.18 x 0.2 inches |
| Item Weight | 0.02 Kilograms |
| Manufacturer | HXJNLDC |
| Model Name | 503040 |
| Model Number | 503040 |
| Number of Batteries | 1 C batteries required. (included) |
| Recommended Uses For Product | GPS, Radio, Watch |
| Reusability | Rechargeable |
| UPC | 054114076826 |
| Unit Count | 1.0 Count |
| Voltage | 3.7 Volts (DC) |
M**N
Quality Battery
Battery works great! I used it to transform some wired headphones into wireless using a Bluetooth receiver. I cut the connector pin on the end off and soldered the 2 wires onto the board and now I have a better sound experience than you can buy in wireless headphones with a battery that now lasts over a week of 24/7 use between charges! It's been like 2 years so far with zero issue. This battery does have overcharge protection. And if you need to replace the wires, it has convenient solder points.
D**.
Works Great in Cozmo
Works great in Cozmo toys. Perfect fit. Installation isn't too hard but does require some time and patience. See the picture here of my son's Cozmo torn down to the point where the battery can be replaced. It looks like a lot of pieces but everything disassembles easily and goes back together pretty easy too. The head is a little tricky as there is a small spring that you have to fight as you put it together, but isn't too hard once you figure it out. Sort of like a puzzle. There is a video on YouTube by John that is super helpful. Just watch that once and you'll have it figured out. The hardest part for most people will be just soldering the wires to the circuit board. This battery comes with a JST plug, but you have to cut that off, strip the wires, and then solder them to the board. It's pretty trivial if you know how to solder, but could trip up people who've never used a soldering iron. You'll need to cut the red wire shorter and leave the black wire longer, since the leads come out the same side of the battery, so it's close to the positive tab on the board, but the negative soldering tab is on the other side. Anyway, so far so good. Cozmo is up and running for last few days now with no issues. Haven't timed the battery life, but so far it lasts longer than my son's interest in it for any given moment. Note that it charges quite fast too. So you can play with this thing off and on all day long as long as you park Cozmo on his home charger between plays. Can recommend this battery. And watch John's tutorial too. Happing fixing!
R**G
Nice replacement for my Skybell HD V4
Bought a house with an expensive Skybell HD V4 Video Doorbell. The thing was working in short bursts, couldn't figure it out. Checked the connections, all was good. Found that the battery on these would expand and die, and that's what happened to mine. I pulled mine apart and found I needed a new battery. I found this replacement on Amazon. Don't do what I did....I threw out the old one before the new one arrived. The plug is not an exact match. You need to splice the wires from the old battery to the new one. The plug is slightly different. Since I didn't have the new one, I improvised. I followed my college engineering training. Step 1: Is it working now? No Step 2: Does the part jam? Yes, the plug doesn't fit cleanly. Step 3: If this battery doesn't work, whats the alternative? Spend $250 for a new doorbell Step 4: Follow the old adage of: If it jams, force it, if it breaks, it needed fixing anyway. I jammed the plug into the socket on the camera using a pair of needle-nose pliers and got it working. The doorbell has been working the last month without issues. I would call this battery a replacement, even if it was a bit more difficult due to me shooting myself in the foot throwing the old one away before I took the plug.
T**M
Good
Good product fixed my doorbell camera install fit price was good. Excellent product.
K**N
Bug in cozmo software
Battery is good but now there is a bug with the cozmo app and currently doesn't work
B**N
Great Replacement for Anki Cozmo in 2024
Worked great to replace my failing Anki Cozmo battery from 5 years ago. The double capacity is a great plus, although you'll probably get bored before it dies anyways. It does take slightly longer to charge though with the larger capacity, about 2 times longer. Would recommend for anyone who wants to replace their failing Anki Cozmo battery!
M**L
Easy to install
Installed this into a Cozmo Robot and it worked great, easy 2 solder connections and that was it.
S**L
Worked great for 3 weeks.
Using rhis battery in a camera monitor, it held a charge all day long for about 3 weeks. Then, on the fourth week it started draining really fast. Now it shows full charge when it's plugged in and within 2 hours of unplugging it goes dead. Just checked amamzon and the return window ended yesterday...
Trustpilot
2 weeks ago
5 days ago